source: psi/trunk/src/tools/idle/idle_win.cpp

/*
 * idle_win.cpp - detect desktop idle time
 * Copyright (C) 2003  Justin Karneges
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include"idle.h"

#include<qlibrary.h>
#include<windows.h>

typedef struct tagLASTINPUTINFO {
        UINT cbSize;
        DWORD dwTime;
} LASTINPUTINFO, *PLASTINPUTINFO;

class IdlePlatform::Private
{
public:
        Private()
        {
                GetLastInputInfo = 0;
                IdleUIGetLastInputTime = 0;
                lib = 0;
        }

        BOOL (__stdcall * GetLastInputInfo)(PLASTINPUTINFO);
        DWORD (__stdcall * IdleUIGetLastInputTime)(void);
        QLibrary *lib;
};

IdlePlatform::IdlePlatform()
{
        d = new Private;
}

IdlePlatform::~IdlePlatform()
{
        delete d->lib;
        delete d;
}

bool IdlePlatform::init()
{
        if(d->lib)
                return true;
        void *p;

        // try to find the built-in Windows 2000 function
        d->lib = new QLibrary("user32");
        if(d->lib->load() && (p = d->lib->resolve("GetLastInputInfo"))) {
                d->GetLastInputInfo = (BOOL (__stdcall *)(PLASTINPUTINFO))p;
                return true;
        }
        else {
                delete d->lib;
                d->lib = 0;
        }

        // fall back on idleui
        d->lib = new QLibrary("idleui");
        if(d->lib->load() && (p = d->lib->resolve("IdleUIGetLastInputTime"))) {
                d->IdleUIGetLastInputTime = (DWORD (__stdcall *)(void))p;
                return true;
        }
        else {
                delete d->lib;
                d->lib = 0;
        }

        return false;
}

int IdlePlatform::secondsIdle()
{
        int i;
        if(d->GetLastInputInfo) {
                LASTINPUTINFO li;
                li.cbSize = sizeof(LASTINPUTINFO);
                bool ok = d->GetLastInputInfo(&li);
                if(!ok)
                        return 0;
                i = li.dwTime;
        }
        else if(d->IdleUIGetLastInputTime) {
                i = d->IdleUIGetLastInputTime();
        }
        else
                return 0;

        return (GetTickCount() - i) / 1000;
}